It's happened with my last 3 Samsungs which are all meant to be waterproof. It hasn't let me charge for 23 hours now, I have had to use a wireless charger... I'm never buying a Samsung again solely because of this
The note 10 is not waterproof, it is water resistant. Take a blow dryer and hold it a few inches away from the port. Then try to take a cotton swab and clean the port out. Put the charger inside of the port and restart the phone while the charger is plugged in
So here is my experience. I took my S8+ many times to swimming pool (5 ft pool). I used to get this notification but I used a dryer to dry it and it used to go away.
One time, I went on a cruise and accidentally I took my wife's Iphone X to a 5ft pool. It was completely dead. Luckily we had a Apple care plus plan, so we got a new phone for $100 but you can choose to deal with notification or switch to iphone and brick the device when it submerges in water. Good day!